Split-end bearing pile



June 28, 1960 u. w. STOLL- 2,942,426

SPLIT-END BEARING PILE Filed June 4, 1954 I: INVENTOR. w w j BY 36 Gig'9 44- /4 4TTORNEYS.

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' to facilitate penetration of the soil, an

The invention described herein may fb'e manufactured .and'used'by orforthe Government oftheiUnited States of America for governmental purposeswithout the paymehtof any royalties thereon or therefor. I p

This invention relates to a pile having its lower end or base formed tobe expandedafter' the pile is driven into "the ground.

In a preferredembodiment, the pile, in the form of a metal tube havingpre-weakenedsections provided with radial fins, is .provided with aninner drive rod which takes most of the driving stress. The drive" rodis provided with a separable plug to facilitate penetration into thesoil, and has a tapered shoulder .portion ofgreater diameter than thetube. when the pile has bee'nidriven to the desired depth, the drive rodis withdrawnfandthe ,"pile *drivinghamm'er is applied-directlyto thetub'ejcausing the lowerendof thetube, with its attached fins, to a be:spread outwardly to form an expanded base capable of sus'tainiiig greatbearing loads.

It is an object of the invention to provide a pile having high pullingresistance and load supporting capacity.

i A furthe'r object ofthe inventionis to provide an im-' proved pile ofsimple design and economical to manufacture and install.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following description.

Fig. 1 is a view in longitudinal section of a pile embodying theinvention;

Fig. 2 is an enlarged view in elevation of the lower end of the pile inunexpanded condition;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on the line 4-4 of Fig.2;

Fig. 5 is a view in elevation of the pile with its lower end inpartially expanded condition; and

Fig. 6 is a similar view showing the base fully expanded.

The pile shown in the drawing consists of a pipe or tube 10 having itslower end formed with a plurality of longitudinal slots 12 which dividethe tube into a number of segments 14. To each segment is secured as bywelding a fin 16 having a tapered forward end 18 and an inclined rearedge 20 designed to rest against the periphery 'of'the tube when thelower end or base of the tubular pile is expanded. In order tofacilitate bending of the segments in the expanding operation, it isadvisable to form a portion 22 of the tube to a square section, as shownin Figs. 2 and 3, the lower end of the tube remaining cylindrical asshown in Fig. 4.

For the driving operation, a driving rod 30 is provided for insertion inthe tube 10 and is formed at its upper end with an enlarged cap 32 whichextends over the top of the tube to transmit driving force thereto. Inthe lower end of the tube 10 is placed a penetrating member or plug 34having a lower surface 36 in conical form face or shoulder $8 designedto exert sgemien s 14 and 'fins shan receive driving-forcefrom; drivinglod' ispreferablymadeofconcrete.

'In "order to empl-ac'e the ile, the magnum; 30 are inserted in place inheavywalld-tube-br as shown in Fig. l and' driving blows are 5 3 51 cap'32. Because the shell or't ibe l fl nieets h I ance, the major forceofthepile' drivingliammer is taken 7 by the rod'30, v vhichtransmitslthe ,forceftof-the' 34. Whenthe, pile is driven nearly to ithe desired depth; the

driving rod '30' isfwithdrawn, andhaminer blows I "re" a'pplied directlyto the upper-'eiid-of thetube Tlfe' lower ends of segments 14 tlieinimpingejforcefilllyfupon ithe surface 38 oftherelativelystationaryplugi34,"wliich' acts ias a'cam 'inforcingthemoutwardly as indicated in'Fig.

5," bending of I the tube material occurring inthefsquare section 22 atthe base "ofthe fins 16 iAfte'rfthetpile-lias been. thus'driven througha; predetermined distance, the

edges .20 of the fins will have been movedinto c'omact wim the twall'iof the t be 10; and "the base will' b'e" fully expanded as 'shownin'Fig. 6 Q'Iheplu'g' 34 remains as=a 'perman'ent'part' of theexpandedba's'epositions shown 'in Fig. 1 to" the positions-shown in Fi 6.involvesbut little lateral displacement of tliefs'oil. [More- 6.' Thexpa e assent whichplug 34ft ms a part, has an areawhichenables the pileto sustain 'lo'a' base, tliisf'eifect beingiheig'htened i by the.arrange 35' i It wi-ll be seen that the. movemenfof iinsllS fromtheover, as the segmentsi'l iaie mov'ed downwardly and outwardly, theirundefs idesact to consolidate andfcdr'npact the underlyingsoilgeneiially indic times in excess of the capacity of a pile withoutthe segments, 'which t'o "some degree"en'clo'se1 a mass of soil. It isnotnecessary to fill the ti1b'e =concft'e in order tonne-teaseas beaitngarea, that function being performed by plug 34. As may be noted,obviously fins 16 prevent the tube 10 from turning or rotating as it isbeing driven into the bearing strata and prevent its rotation afterbeing driven into place.

Obviously many modifications and variations of the I present inventionare possible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise'than as specifically described.

What is claimed is:

1. The method of driving a high compression load bearing pile, whichmethod comprises:

disposing a plug in the ground at the location where the pile is to bedriven, said plug having a drivingpoint adapted to enter the ground, acylindrical shank portion with a driving top substantially normal to theaxis of said plug, a central cylindrical section of greater diameterthan said shank portion, and an inwardly tapered I conical shoulderconnecting said central cylindrical portion and said cylindrical shank;

disposing the bottom end of a vertical heavy walled tube over thecylindrical shank portion of said plug and permitting the said bot-tomend of said tube to rest on said inwardly tapered conical shoulder ofsaid plug, said tube having a plurality of longitudinal slots formed inthe bottom end of said tube, an equal plurality of segments formed insaid bottom end of said tube by said slots, means in said tube at theupper end of said seg- V .P en e {use 8 1269 the driving top of saidplug, said driving rod having an enlarged drivingcapat its upperendwhich restson the top'of said tube; :AJ-Q' applying a driving force tosaid driving cap whereby said plug and said heavy walled tube are driveninto the said rod being of a diameter substantially equal to the innerdiameter of said tube and resting on ground strata the desired distance,the major portion of M the bottom portion of said tube is drivendownwardly past said plug, forcing said segments and radial finsdownwardly and outwardly substantially beyond the diameter of saidcentral cylindrical portion of said plug until the upper edges of'saidradial fins abut against the cylindrical wall of said vertical tubeadjacent the upper ends of said segments thereby limiting the furtheroutward bending of said segments and transmitting the compressive loadreaction forces acting vertically upward under said segments to saidheavy-walled vertical tube whereby said plug, said outwardly bentsegments, and said radial fins comprise a non-rotativemaximumcompression load supporting base for said pile.

2. A high compression load bearing pile comprising in combination:

a heavy walled cylindrical metal tube of sufiicient length to form aload bearing pile after being driven into a load bearing ground strata;

a plurality of longitudinal slots formed in the lower end of said tubeto provide an equal plurality of segments; 1 f t means located at theupper ends of said segments for facilitating their bending outwardly assaid pile is driven ing the outward bending of said segments, said meansbeing adapted to support a compressive load between each of saidsegments and the wall of said tube adjacent to the upper end of saidsegments and comprising a longitudinally extending radial fin secured toeach segment, each fin increasing in radial extent in an upwarddirection and having an upper edge disposed at an acute angle to saidtube; and n separable ground penetrating plug means inserted in thelowerend of said heavy walled metal tube and forcing said segmentstobend outwardly into said ground strata until mid compressive loadmeans associated with said segments abut against the outer surface ofthe said tube as the lower end of said tube is driven downwardly overand past said ground penetrating means, said plug means comprising acylindrical shank adapted to be inserted into the lower end of saidtube, a conically pointed lower end adapted to penetrate said groundstrata, a central cylindrical section having a diameter greater than theexternal diameter of said tube and an inwardly tapered conical sectionjoining said central section and said shank further characterized bymaking the acute angle formed between the upper edge of said radial finand the wall of said tube substantially equal to the angle of theinwardly tapered conical section joining said central section and saidshank of said plug with the longitudinal axis of said shank.

References Cited in the file of this patent UNITED STATES PATENTS1,035,893 Miller Aug. 20, 1912 1,224,925 Hindmarsh May 8, 1917 1,413,503Stevens Apr. 18, 1922 1,600,020 Tomkinson Sept. 14, 1926 2,465,557Thornley Mar. 29, 1949 2,588,712 Ferris Mar. 11, 1952 FOREIGN PATENTS896,328 Germany Nov. 12, 1953

